If you're going to paint the engine bay, use semi-gloss black. It'll look much nicer than gloss.
As has been said, it wants a paint and a tidy. Why not lift the engine and spend a week painting it the same colour as the car will be - Azure blue wasn't it?
Then maybe make all the other colurs in there blue as well maybe.
I've got a pic of the best engine bay I've ever seen (and no, it's not mine) ...
Minimalism I think they call it - just where everything has gone though I'm not sure ...
Semi-gloss and semi-flat are way different..